The standard setting organization 3GPP (the 3rd Generation Partnership Project) has conducted a study of a LTE-Advanced (Long Term Evolution Advanced: LTE-A) scheme which is an advanced type of the LTE (Long Term Evolution) scheme. In connection with the LTE-A scheme, a CoMP (Coordinated Multi-point transmission/reception) technique has been under consideration as a technique for fulfilling system performance requirements, such as a frequency utilization factor (required system capacity) and cell edge throughput. The CoMP technique is one by means of which a wireless communication terminal (UE: User Equipment) transmits and receives a signal by use of a plurality of sectors or cells. Under the technique, a plurality of cells perform transmission and reception in coordination with each other, so that reducing interference from another cell and augmenting electric power of a desired signal can be realized.
Roughly two types are conceivable as a method for realizing the CoMP technique. A method of one type is a CoMP technique utilized between a remote base station (RRE: Remote Radio Equipment), such as an outlying base station, and an integrated control base station that performs integrated control of a plurality of pieces of RRE. Since the RRE and the integrated control base station are connected to each other by use of an optical fiber, a signaling delay is little. In addition, since the integrated control base station can perform integrated control of resources to be employed by the CoMP, implementing the CoMP technique is comparatively easy.
A method of another type is a CoMP technique employed among a plurality of independent base stations. In an UMTS system in which signals are simultaneously transmitted from a plurality of base stations, an RNC that is an integrated control station has a function of managing resources of the plurality of base stations, and each of the base stations controls its resource with respect to the RNC. An LTE system, however, does not have any RNCs, and each base station has a resource management function that is carried out by the RNC. Therefore, under the CoMP technique that controls resources of a plurality of independent base stations, the independent base stations must perform a negotiation with each other over resources for CoMP transmission purpose. To be specific, one base station (a master base station) among base stations that are to carry out CoMP communication makes a request to another base station (a slave base station) that carries out coordinated multiple point transmission/reception for a CoMP transmission resource, thereby assuring the CoMP transmission resource. Moreover, the master base station performs scheduling for the terminal that is to carry out the CoMP communication, by use of the thus-assured CoMP transmission resource. In the meantime, the slave base station receives from the master base station information about a resource scheduled by the master base station. Under the CoMP technique, data to be used for the CoMP communication are transferred to the slave base station by way of the master base station, whereby the plurality of independent base stations actualize coordinated multiple point transmission/reception.